Backyard Aquaponics
A place to discuss aquaponics

Temperature being an important factor...

Glad you chimed in Ryan, cheers, I will take all info on board... exactly what I was after.

Hey Ryan, with your old backyard raft demo, and Im ok if you would rather not share, but did you add any other sources of nutrient for plant uptake after your filter bins?

I should add I did grow some good stuff in my DWC but I just always felt I could have done better and I want more control over my inputs. My next system is going to be a bit more involved and I will be putting more time into nutrient control. The cool part is Im more than happy and excited to experiment and develop my own knowledge for my particular system and circumstances. Thats what is the fun bit of AP is for me.

Ryan, or anyone: how would one calculate waste in the system. Is it roughly the same as food rate? Providing they are consuming 99% of the food, which is the goal. Anybody know a way to remove "sludge" (lack of better word) from roots in a DWR? I'm getting better growth since I installed the 60 micron filter, but now it's needing changed more then the twice daily that I can always do it. The water pressure is dropping in the DWF bed and it isn't getting the once per hour turn over that I'm shooting for. I put a few different plants in just to see how they did. Mostly lettuce, but tomato, strawberry, and broccoli plants are growing very well, and all have very clean roots. The lettuce has been in the longest and has the most muck on the roots. I also added more aeration, and that also seemed to help. Once I harvest the lettuce, I will clean any sludge in the DWR bottom and I'm sure next crop will do much better. Viewflow filter is not going to work, or at least not the 1" size....not enough filter area to keep from cleaning it too often. Has anyone tried the larger 1.5-2" versions? I've used them for irrigation purposes, including reclaimed water and they work pretty well...just on the pricey side.

Isn't that the same thing in different words?

The volume of waste will be determined by the feeding rate. I guess it could be a specific concern if a significant amount of food was getting wasted because uneaten food will produce more "waste" than eaten food. The sizing of mineralisation tanks of course has to take into account the residence time which will vary according to the parameters you listed. Again the volume of waste delivered to the MT by mechanical filtration comes back to how much you feed in the first place. If the mechanical filtration does not deliver all the solid wastes from the fish food are they not going to build up in the system and cause problems?

If I have missed a distinction you are trying to make please correct me.

The calculations I did was based on satisfying the Biological Oxygen Demand for a given amount of waste. In a 12KL tank how much waste are you adding on a daily basis and how many kWhr a month does your system use?

Hey bud, no problem
I added chelated iron, KOH and CaOH but that's it. No secret kelp juice from the moon haha


Stuart- the difference would be if you took a 30 micron drum filter, 1000 gal Rakocy clarifier, 100 gal Radial flow seperator or 300gal swirl filter...

Though total waste created is based on feed, the total waste water removed daily in order to get that waste out of the system will be vastly different. Thus the M tank sizing, design and implimentation will vary depending on the mechanical filtration in the design.

I'll try to answer more after I eat dinner

I would have thought that the back flush from any type of filtration would go into the MT so the amount of waste it had to handle would stay the same.

Are you saying that you are only processing a portion of the solid wastes?